[libc-commits] [libc] [llvm] [libc][math] Refactor ffmal to Header Only. (PR #176989)

Harrishan Raveendran via libc-commits libc-commits at lists.llvm.org
Tue Jan 20 10:21:25 PST 2026 

https://github.com/Harrish92 created https://github.com/llvm/llvm-project/pull/176989

Closes #175326


>From 35a918df3e39e1a4ecfdeb3d7847844bd692b3a7 Mon Sep 17 00:00:00 2001
From: Harrish92 <harrishan.raveendran at epfl.ch>
Date: Tue, 20 Jan 2026 19:00:31 +0100
Subject: [PATCH 1/2] [libc][math] Refactor `ffmal` to Header Only.

---
 libc/shared/math.h                            |  1 +
 libc/shared/math/ffmal.h                      | 23 ++++++++++++++++
 libc/src/__support/math/CMakeLists.txt        |  8 ++++++
 libc/src/__support/math/ffmal.h               | 27 +++++++++++++++++++
 libc/src/math/generic/CMakeLists.txt          |  2 +-
 libc/src/math/generic/ffmal.cpp               |  6 ++---
 libc/test/shared/CMakeLists.txt               |  1 +
 .../llvm-project-overlay/libc/BUILD.bazel     | 10 ++++++-
 8 files changed, 72 insertions(+), 6 deletions(-)
 create mode 100644 libc/shared/math/ffmal.h
 create mode 100644 libc/src/__support/math/ffmal.h

diff --git a/libc/shared/math.h b/libc/shared/math.h
index d58238703701d..d13360daf6720 100644
--- a/libc/shared/math.h
+++ b/libc/shared/math.h
@@ -59,6 +59,7 @@
 #include "math/expm1f.h"
 #include "math/expm1f16.h"
 #include "math/f16fma.h"
+#include "math/ffmal.h"
 #include "math/frexpf.h"
 #include "math/frexpf128.h"
 #include "math/frexpf16.h"
diff --git a/libc/shared/math/ffmal.h b/libc/shared/math/ffmal.h
new file mode 100644
index 0000000000000..5e557cfe3895b
--- /dev/null
+++ b/libc/shared/math/ffmal.h
@@ -0,0 +1,23 @@
+//===-- Shared ffmal function -----------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SHARED_MATH_FFMAL_H
+#define LLVM_LIBC_SHARED_MATH_FFMAL_H
+
+#include "shared/libc_common.h"
+#include "src/__support/math/ffmal.h"
+
+namespace LIBC_NAMESPACE_DECL {
+namespace shared {
+
+	using math::ffmal;
+
+} //namespace shared
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif //LLVM_LIBC_SHARED_MATH_FFMAL_H
diff --git a/libc/src/__support/math/CMakeLists.txt b/libc/src/__support/math/CMakeLists.txt
index bf1c4463b8066..985ed97a5cf50 100644
--- a/libc/src/__support/math/CMakeLists.txt
+++ b/libc/src/__support/math/CMakeLists.txt
@@ -648,6 +648,14 @@ add_header_library(
     libc.include.llvm-libc-macros.float16_macros
 )
 
+add_header_library(
+	fmmal 
+  HDRS
+    ffmal.h
+  DEPENDS
+		libc.src.__support.FPUtil.fma
+)
+
 add_header_library(
   ilogbf16
   HDRS
diff --git a/libc/src/__support/math/ffmal.h b/libc/src/__support/math/ffmal.h
new file mode 100644
index 0000000000000..10c64c1178a5d
--- /dev/null
+++ b/libc/src/__support/math/ffmal.h
@@ -0,0 +1,27 @@
+//===-- Implementation header for ffmal ------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC___SUPPORT_MATH_FFMAL_H
+#define LLVM_LIBC_SRC___SUPPORT_MATH_FFMAL_H
+
+#include "src/__support/FPUtil/FMA.h"
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+namespace math {
+
+static constexpr float ffmal(long double x, long double y, long double z) {
+	return fputil::fma<float>(x, y, z);
+}
+
+} // namespace math
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC___SUPPORT_MATH_FFMAL_H 
diff --git a/libc/src/math/generic/CMakeLists.txt b/libc/src/math/generic/CMakeLists.txt
index b578d1805f2a8..23f17469640c7 100644
--- a/libc/src/math/generic/CMakeLists.txt
+++ b/libc/src/math/generic/CMakeLists.txt
@@ -3406,7 +3406,7 @@ add_entrypoint_object(
   HDRS
     ../ffmal.h
   DEPENDS
-    libc.src.__support.FPUtil.fma
+		libc.src.__support.math.ffmal
 )
 
 add_entrypoint_object(
diff --git a/libc/src/math/generic/ffmal.cpp b/libc/src/math/generic/ffmal.cpp
index d5cd4f763cbe5..fe4b75423a2e0 100644
--- a/libc/src/math/generic/ffmal.cpp
+++ b/libc/src/math/generic/ffmal.cpp
@@ -7,15 +7,13 @@
 //===----------------------------------------------------------------------===//
 
 #include "src/math/ffmal.h"
-#include "src/__support/FPUtil/FMA.h"
-#include "src/__support/common.h"
-#include "src/__support/macros/config.h"
+#include "src/__support/math/ffmal.h"
 
 namespace LIBC_NAMESPACE_DECL {
 
 LLVM_LIBC_FUNCTION(float, ffmal,
                    (long double x, long double y, long double z)) {
-  return fputil::fma<float>(x, y, z);
+  return math::ffmal(x, y, z); 
 }
 
 } // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/test/shared/CMakeLists.txt b/libc/test/shared/CMakeLists.txt
index cfc2eda1aaec9..5c734973701dd 100644
--- a/libc/test/shared/CMakeLists.txt
+++ b/libc/test/shared/CMakeLists.txt
@@ -55,6 +55,7 @@ add_fp_unittest(
     libc.src.__support.math.expf
     libc.src.__support.math.expf16
     libc.src.__support.math.f16fma
+		libc.src.__support.math.ffmal
     libc.src.__support.math.frexpf
     libc.src.__support.math.frexpf128
     libc.src.__support.math.frexpf16
diff --git a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
index 90b1da0e3376e..2102243044b6c 100644
--- a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
+++ b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
@@ -2814,6 +2814,14 @@ libc_support_library(
     ],
 )
 
+libc_support_library(
+    name = "__support_math_ffmal",
+    hdrs = ["src/__support/math/ffmal.h"],
+    deps = [
+			":__support_fputil_fma",
+    ],
+)
+
 libc_support_library(
     name = "__support_math_frexpf128",
     hdrs = ["src/__support/math/frexpf128.h"],
@@ -4138,7 +4146,7 @@ libc_math_function(
 libc_math_function(
     name = "ffmal",
     additional_deps = [
-        ":__support_fputil_fma",
+        ":__support_math_ffmal",
     ],
 )
 

>From 2c95068ed5f8a4ebe8c9a332c5c81b41d2d93863 Mon Sep 17 00:00:00 2001
From: Harrish92 <harrishan.raveendran at epfl.ch>
Date: Tue, 20 Jan 2026 19:14:54 +0100
Subject: [PATCH 2/2] style: run clang-format

---
 libc/shared/math/ffmal.h        | 6 +++---
 libc/src/__support/math/ffmal.h | 7 ++++---
 libc/src/math/generic/ffmal.cpp | 2 +-
 3 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/libc/shared/math/ffmal.h b/libc/shared/math/ffmal.h
index 5e557cfe3895b..6493fbf727782 100644
--- a/libc/shared/math/ffmal.h
+++ b/libc/shared/math/ffmal.h
@@ -15,9 +15,9 @@
 namespace LIBC_NAMESPACE_DECL {
 namespace shared {
 
-	using math::ffmal;
+using math::ffmal;
 
-} //namespace shared
+} // namespace shared
 } // namespace LIBC_NAMESPACE_DECL
 
-#endif //LLVM_LIBC_SHARED_MATH_FFMAL_H
+#endif // LLVM_LIBC_SHARED_MATH_FFMAL_H
diff --git a/libc/src/__support/math/ffmal.h b/libc/src/__support/math/ffmal.h
index 10c64c1178a5d..872ce70ed78b2 100644
--- a/libc/src/__support/math/ffmal.h
+++ b/libc/src/__support/math/ffmal.h
@@ -1,4 +1,5 @@
-//===-- Implementation header for ffmal ------------------------------------===//
+//===-- Implementation header for ffmal
+//------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -17,11 +18,11 @@ namespace LIBC_NAMESPACE_DECL {
 namespace math {
 
 static constexpr float ffmal(long double x, long double y, long double z) {
-	return fputil::fma<float>(x, y, z);
+  return fputil::fma<float>(x, y, z);
 }
 
 } // namespace math
 
 } // namespace LIBC_NAMESPACE_DECL
 
-#endif // LLVM_LIBC_SRC___SUPPORT_MATH_FFMAL_H 
+#endif // LLVM_LIBC_SRC___SUPPORT_MATH_FFMAL_H
diff --git a/libc/src/math/generic/ffmal.cpp b/libc/src/math/generic/ffmal.cpp
index fe4b75423a2e0..c5d0d421c42a4 100644
--- a/libc/src/math/generic/ffmal.cpp
+++ b/libc/src/math/generic/ffmal.cpp
@@ -13,7 +13,7 @@ namespace LIBC_NAMESPACE_DECL {
 
 LLVM_LIBC_FUNCTION(float, ffmal,
                    (long double x, long double y, long double z)) {
-  return math::ffmal(x, y, z); 
+  return math::ffmal(x, y, z);
 }
 
 } // namespace LIBC_NAMESPACE_DECL

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